U.S. patent application number 13/224774 was filed with the patent office on 2012-03-15 for circumferential blocking device of clamp vanes for turbine engine, with improved radial deployment.
This patent application is currently assigned to SNECMA. Invention is credited to Yvon CLOAREC.
Application Number | 20120063907 13/224774 |
Document ID | / |
Family ID | 43836909 |
Filed Date | 2012-03-15 |
United States Patent
Application |
20120063907 |
Kind Code |
A1 |
CLOAREC; Yvon |
March 15, 2012 |
CIRCUMFERENTIAL BLOCKING DEVICE OF CLAMP VANES FOR TURBINE ENGINE,
WITH IMPROVED RADIAL DEPLOYMENT
Abstract
The invention relates to a device (30) for blockage of vanes in
a circumferential groove (10) of a turbine engine disc, the device
being intended to deploy in a radial direction to be locked in the
circumferential groove open radially. According to the invention,
the blocking device comprises a first and a second piece (32, 34)
designed to deploy in the radial direction by relative displacement
of these pieces in the circumferential direction (23).
Inventors: |
CLOAREC; Yvon; (Ecuelles,
FR) |
Assignee: |
SNECMA
Paris
FR
|
Family ID: |
43836909 |
Appl. No.: |
13/224774 |
Filed: |
September 2, 2011 |
Current U.S.
Class: |
416/220R ;
29/889.21 |
Current CPC
Class: |
Y10T 29/49321 20150115;
F05D 2230/64 20130101; F01D 5/32 20130101; F01D 5/3038
20130101 |
Class at
Publication: |
416/220.R ;
29/889.21 |
International
Class: |
F01D 5/30 20060101
F01D005/30; B21K 25/00 20060101 B21K025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 13, 2010 |
FR |
1057266 |
Claims
1. A blocking device (30) for vanes in a circumferential groove
(10) of a turbine engine disc, said device being intended to deploy
in a radial direction to be locked in said circumferential groove
open radially, characterised in that said blocking device comprises
a first and second piece (32, 34) designed to deploy in the radial
direction by relative displacement of said pieces in the
circumferential direction (23).
2. The device as claimed in claim 1, characterised in that at least
one of said first and second pieces (32, 34) is equipped with a
gripping member (52, 52a) for being taken along relative to the
other piece, according to the circumferential direction.
3. The device as claimed in claim 2, characterised in that the
gripping member is a tab or a cable.
4. The device as claimed in claim 2 or 3, characterised in that the
piece equipped with the gripping member (52, 52a) has a stop (49)
in the circumferential direction.
5. The device as claimed in claim 1, characterised in that at least
one of said first and second pieces (32, 34) has a ramp (48) for
deployment of the device in the radial direction, during relative
displacement of said pieces in the circumferential direction.
6. The device as claimed in claim 1, characterised in that it is
equipped with locking means (68, 70) of the two pieces (32, 34) in
a position deployed radially.
7. A system (60) comprising two pieces intended to enter
respectively in the constitution of two blocking devices (30) as
claimed in claim 1, characterised in that said two pieces are
joined together by said gripping member (52, 52a) on either side of
which they are located.
8. A turbine engine wheel (1) comprising a disc (2) with
circumferential groove (10), vanes (6) whereof the bases (8) are
retained radially by said groove, as well as at least one device
(30) of circumferential blockage of vanes as claimed in claim
1.
9. A turboengine comprising at least one wheel (1) as claimed in
claim 8.
10. A process for installing a blocking device (30) as claimed in
claim 1, in the circumferential groove (10) of a disc (2) of a
turbine engine, characterised in that it comprises the following
steps: placing of said blocking device (30) in the circumferential
groove (10); and deployment of said blocking device (30) in the
radial direction to lock it in said circumferential groove (10), by
relative displacement of said first and second pieces (32, 34) in
the circumferential direction.
Description
TECHNICAL FIELD
[0001] The present invention relates to a wheel of a turbine
engine, comprising a disc and a plurality of hammer clamp vanes
mounted on this same disc, in a circumferential groove of the
latter. The wheel is preferably intended to form an axial
compressor or turbine stage, for the high- or low-pressure
body.
[0002] The invention also relates to a circumferential blocking
device of vanes in the groove of the disc open radially.
[0003] The invention applies in particular to a wheel of a turbine
engine for aircraft, for example of the type for turbojet or
turboprop. It applies more generally to any hammer clamp wheel, for
example for a steam turbine.
PRIOR ART
[0004] Circumferential blocking devices of hammer clamp vanes in
the groove of a turbine engine aircraft disc are known for example
from documents EP 1 621 732, EP 0 305 223, or EP 1 164 251. They
are designed such of that they lock in a determined position of the
groove of the disc, where they can be blocked according to the
circumferential direction, and therefore constitute stops in this
same direction for the vanes. Because of this, the
circumferentially blocked vanes cannot escape from the
circumferential groove into which they were previously introduced,
via an introduction window of their base.
[0005] The locking of a blocking device is usually done by
deploying it in the groove, according to the radial direction. A
first type of deployment is done using elastic means, as is the
case in the two first documents cited hereinabove. However, these
elastic means prove poorly adapted to a high-temperature
environment.
[0006] A second type of deployment is done by screwing, as is known
from the latter document cited hereinabove. However, the screw
system employed is often subject to jamming, requiring partial or
total destruction of the blocking device during dismantling of the
vanes, with the risk of damage to the disc. Also, the presence of
the screw system requires access at the level of the vane platforms
for screwing, which disturbs the flow of the vein.
SUMMARY OF THE INVENTION
[0007] The aim of the invention therefore is to rectify at least
partially the disadvantages mentioned hereinabove, relative to the
embodiments of the prior art.
[0008] For this, the initial object of the invention is a vane
blocking device in a circumferential groove of a turbine engine
disc, said device being intended to be deployed in a radial
direction to be locked in said circumferential groove open
radially. According to the invention, said blocking device
comprises a first and second piece designed to be deployed in the
radial direction by relative displacement of said pieces in the
circumferential direction.
[0009] Thus, the invention is remarkable by its system of
deployment, the design of which limits the number of pieces
required, does not necessarily require access at the level of the
vane platforms, limits the risks of jamming, and also supports a
high-temperature ambience.
[0010] Also, it is particularly easy to handle. By way of
indication, the relative displacement of the two pieces of the
device, in the circumferential direction, can be controlled from
the introduction window of the vane bases.
[0011] Preferably, at least one of said first and second pieces is
equipped with a gripping member allowing it to be taken along
relative to the other piece, according to the circumferential
direction. This gripping member can be a tab or a cable for
example.
[0012] Preferably, the piece equipped with the gripping member has
a stop in the circumferential direction, provided to ensure proper
relative positioning of the two pieces of the blocking device
occupying the configuration deployed.
[0013] Preferably, at least one of said first and second pieces has
a ramp for deployment of the device in the radial direction, during
relative displacement of said pieces in the circumferential
direction.
[0014] Preferably, the blocking device is equipped with locking
means of the two pieces in radially deployed position. The
resulting locking therefore ensures blockage in translation of the
two pieces relative to each other, according to the circumferential
direction.
[0015] The invention also relates to a system comprising two pieces
intended to enter respectively in the constitution of two blocking
devices such as that described hereinabove, said two pieces being
joined together by said gripping member on either side of which
they are located. Thus, actioning the same gripping member
advantageously produces simultaneous locking of two blocking
devices.
[0016] Another aim of the invention is a wheel of a turbine engine
comprising a disc with circumferential groove, vanes whereof the
bases are retained radially by said groove, as well as at least one
circumferential blocking device of vanes such as described
hereinabove. The wheel is preferably provided to enter the
constitution of a compressor stage, high- or low-pressure, but
could alternatively be provided to form a turbine stage of the
turbine engine.
[0017] Another aim of the invention is a turbine engine, preferably
for aircraft, for example of the turbojet or turboprop type,
comprising at least one wheel such as mentioned hereinabove.
[0018] It can alternatively be any other type of turbine engine,
such as a steam or gas turbine.
[0019] Finally, the aim of the invention is a process for
installing a blocking device such as described previously, in the
circumferential groove of a turbine engine disc, comprising the
following steps: [0020] placing of said blocking device in the
circumferential groove; and [0021] deployment of said blocking
device in the radial direction to lock it in said circumferential
groove, by relative displacement of said first and second pieces in
the circumferential direction.
[0022] Other advantages and characteristics of the invention will
emerge from the following detailed and non-limiting
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] This description will be given in reference to the attached
diagrams, in which;
[0024] FIG. 1 illustrates a perspective view of part of a wheel of
compressor stage of a turbojet, according to a preferred embodiment
of the invention;
[0025] FIG. 2 shows a partial plan view of the disc of the wheel of
FIG. 1;
[0026] FIG. 3 illustrates an exploded view in perspective of a
circumferential blocking device of vanes, designed to equip the
wheel shown in FIG. 1, this device in the form of a preferred
embodiment of the present invention;
[0027] FIGS. 4a and 4b show sectional views outlining the operation
of the blocking device shown in the preceding figure,
[0028] FIGS. 5a and 5b respectively show the blocking device in
retracted configuration and in deployed configuration, in the
circumferential groove of the wheel disc, these views being taken
along the line V-V of FIG. 2;
[0029] FIG. 6 illustrates one of the pieces of the blocking device,
according to another preferred embodiment;
[0030] FIG. 7 illustrates one of the pieces of the blocking device,
according to yet another preferred embodiment;
[0031] FIGS. 8a to 8c outline a process according to a preferred
embodiment of the invention, for installing the blocking device
integrating the piece shown in FIG. 6;
[0032] FIG. 9 illustrates a perspective view of a system comprising
two pieces intended to respectively enter the constitution of two
blocking devices such as that shown in FIG. 6, the system in the
form of a preferred embodiment of the invention;
[0033] FIG. 10 is a view similar to that of FIG. 9, the system in
the form of another preferred embodiment of the invention;
[0034] FIGS. 11a and 11b outline a process according to a preferred
embodiment of the invention, for installing two blocking devices
integrating the system shown in FIG. 9;
[0035] FIGS. 12a and 12b outline a process similar to that shown on
FIGS. 11a and 11b, in the form of an alternative embodiment;
[0036] FIG. 13 outlines a process similar to that shown in FIGS.
12a and 12b, in the form of another alternative embodiment,
illustrating by the addition of a positive system for keeping
pieces of the blocking device in tangential/circumferential
position;
[0037] FIG. 14 illustrates a perspective view of the system
employed for executing the process outlined in the preceding
figure;
[0038] FIG. 15 is a view similar to that of FIG. 14, the system in
the form of another preferred embodiment of the invention; and
[0039] FIGS. 16a and 16b illustrate views outlining the dismantling
of blocking devices, after they are locked by the process shown in
FIG. 13.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] In reference first to FIGS. 1 and 2, these show a wheel part
1 of a high-pressure compressor of an aircraft turbine engine such
as a turbojet, this wheel 1 preferably intended to constitute part
of one of the rear stages of this high-pressure compressor, in the
form of a preferred embodiment of the present invention.
[0041] The wheel 1 first comprises a disc 2 having a central axis 4
corresponding to the longitudinal axis of the turbojet. At the
level of a circumferential radial end of this disc 2 the latter
bears a plurality of so-called hammer clamp vanes 6, which are
therefore distributed angularly right around the central axis 4.
These hammer clamp vanes 6 specifically comprise a vane base 8
intended to be housed in a circumferential groove 10 of the disc 2,
this circumferential groove of the disc located therefore at the
level of a radial end of the disc 2 and being open radially to the
exterior. As is disclosed by the expert, this circumferential
groove 10 has a transversal cross-section in the form of dovetail,
delimited especially by a base 13 and by two annular lateral rims
11, of enlarged thickness and placed opposite each other. In other
terms, the circumferential groove 10 overall has the form of a C
opening radially to the exterior, and letting the standard of the
vane, as will be described now, pass between the two ends of this C
defined by the rims 11.
[0042] In fact, as known to the expert each vane 6 successively
comprises in a radial direction to the interior, represented by
arrow 12, a blade 14, a platform 16, a standard 18 and finally the
abovementioned vane base 8. It is noted here that the blade
conventionally a leading edge 20 and a trailing edge 22, the
trailing edge 22 being offset towards the circumferential direction
23 of the disc relative to the leading edge 20 according to a given
offset, a function of the profile of this blade. Next, the platform
has a circumferential length much longer than that of the blade 14
it supports, and is preferably intended to come close to the
platform of the two vanes 6 of the assembly directly adjacent.
Thus, when the assembly of vanes is mounted inside the groove 10,
the platforms 16 of these vanes form substantially a crown centred
on the axis 4, covering the annular rims 11.
[0043] Also, it is noted that the radial holding to the exterior of
each vane 6 relative to the disc 2 is ensured conventionally by the
contact of two footprints 17 made on the base 8 and oriented
substantially radially to the exterior, respectively with the two
enlarged rims 11 of the circumferential groove 10.
[0044] The groove 10 has an introduction window for vane bases 15,
via which a vane base can be introduced into this groove, by radial
displacement of the relevant vane. For this, the window 15 is made
from two axial notches made respectively in the two rims 11, the
distance between the two notch bases opposite corresponding
substantially to the axial length of a vane base 8.
[0045] Once inserted in the groove 10 by the window 15, each vane
is then shifted circumferentially within the groove 10. Also, the
vanes are kept in a circumferential position in the groove by means
of one or more blocking devices (not shown in FIGS. 1 and 2), which
are also subject matter of the present invention, and a preferred
embodiment of which will now be described in reference to FIG.
3.
[0046] This figure illustrates a blocking device 30 comprising two
distinct parts, a first part 32 called radially external, and a
second part 34 called radially internal, taking the form of a
wedge.
[0047] The first part 32 overall takes the form of a vane base, in
particular with two footprints 36 arranged at the axial ends, and
oriented substantially radially to the exterior. As will be
specified in greater detail hereinbelow, these two surfaces 36 are
intended to contact respectively the two enlarged rims 11 of the
circumferential groove 10. A circumferential stop 38 extends
radially to the exterior from these two surfaces 36. As known, this
stop 38 is intended to be introduced to an opening of the groove
10, referenced as 19 in FIGS. 1 and 2. This opening 19 is similar
to the introduction window 15, but has reduced axial length at the
same time allowing the stop 38 to be introduced therein when the
piece 32 is shifted radially to the exterior, and to the surfaces
of radial stop 36 to be retained by the remaining edges of the
groove 10. Holding the stop 38 in the opening 19, because of
several contact surfaces 40 made on the stop 38, permits
circumferential blockage of the first piece 32 in the groove 10. In
this way, the body 42 of this first piece can in turn act as
circumferential blockage for the vane bases, because of its two
opposite surfaces of circumferential stop 44.
[0048] The second part 34 overall comprises two support surfaces of
the first part 32, the second surface 46b being elevated radially
relative to the first surface 46a, and being attached to the latter
by a ramp 48. This second piece 34, which therefore extends
circumferentially between the two support surfaces 46a, 46b, has a
stop 49 in the circumferential direction, this stop 49 located at
the end of the second support surface 46b, by being oriented
radially to the exterior.
[0049] Consequently, the blocking device 30 is designed to pass
from a retracted state such as shown in FIG. 4a, to a deployed
state such as shown in FIG. 4b, by simple relative circumferential
displacement between the pieces 32 and 34. In fact, in the
retracted state, the first piece 32 is supported by the first
surface 46a lowered radially. The radial extent of the device 30 is
now reduced. By shifting the second part 34 according to the
circumferential direction 23, relative to the first part 32
remaining fixed in this same direction, this first part slides on
the ramp 48, then reaches the second surface 46b on which it is
elevated radially. The device 30 adopts a deployed configuration in
which its radial dimension is increased, which lets it unlock in
the groove 10, as will now be described in reference to FIGS. 5a
and 5b.
[0050] In fact, FIG. 5a shows the blocking device 30 in retracted
configuration, in which the first piece 32 is supported by the
first surface 46a. The first piece is located close to the base 13
of the groove 10, and its stop 38 is too retracted radially to the
interior to cooperate with the opening 19. However, after
circumferential displacement of the second piece 34, the blocking
device 30 attains its deployed configuration shown in FIG. 5b, in
which the first piece 32 is supported by the second surface 46b. In
this state which has brought the first piece 32 to elevate
radially, the stop 38 is introduced in the opening 19, resulting in
contact of the surfaces 40 with the flanks 50 of the opening 19,
and therefore circumferential retention of the first piece 32 in
the groove 10, in both directions. This circumferential retention
is accentuated by the radial support of the footprints 36 against
inner surfaces 37 of the rims 11, which creates radial tightening
of the blocking device 30 in the groove 10.
[0051] By way of indication, it is noted that relative
circumferential displacement of the two pieces can be done in any
way deemed appropriate by the expert, for example by using adapted
tools. FIG. 6 shows an embodiment in which this displacement is
employed.
[0052] Effectively, FIG. 6 shows that the second piece 34 of the
blocking device 30 can be equipped with a gripping member making it
easier to bring it along relative to the first piece, according to
the circumferential direction. Here, the member takes the form of a
tab 52 extending circumferentially from the first support surface
46a, in the direction opposite to that of the stop 49. As an
alternative, the gripping member can be a cable 52a, as shown in
FIG. 7.
[0053] It is noted that the gripping member can be designed to act
by thrust and/or by traction.
[0054] In reference now to FIGS. 8a to 8c, these show a process for
installing the blocking device 30.
[0055] First of all, the second piece 34 of the device is
introduced in the groove 10, to rest in the base 13 of the latter.
This introduction can be done easily, for example by introducing it
via the enlarged window 15, then by having it slide
circumferentially in the base of the groove to bring it into the
preferred position, in which the first support surface 46a is
located radially opposite the opening 19 as outlined by dotted
lines.
[0056] If the stop 49 in the form of a picker cannot pass below the
vane bases already in place in the groove 10, the base 13 of the
latter can be machined to enable such passage.
[0057] Next, the first piece 32 is introduced in the groove 10 via
the introduction window 15, then slid circumferentially to come to
rest on the surface 46a, at the base of the ramp 48, as shown in
FIG. 8a. This retracted configuration, in which the first piece 32
is located radially opposite the opening 19, is maintained by
gravity.
[0058] Next comes introduction of the remaining vanes 6,
conventionally via the introduction window of the vane bases 15.
These can be for example of two vanes 6 introduced in the
circumferential groove 10 after the device 30 is placed in this
same groove. The introduction of the second vane 6 is made possible
by circumferential displacement of the device 30 and of the first
of the two vanes 6 and of all the elements present in the groove 10
to give free access to the window 15. Next, all the elements
present in the groove 10 are chocked circumferentially in the
groove 10 to return the first piece 32 radially opposite the
opening 19. In this state shown in FIG. 8b, the last two vanes
introduced 6 are placed on either side of the introduction window
15, preventing them from escaping via the latter. Also, contact
between the stop 44 of the first piece 32 and the base 8 of the
vane directly adjacent keeps the circumferential position of all
the vanes 6 within the groove 10.
[0059] Next, a deployment step of the blocking device 30 is
undertaken, by circumferential displacement of the second piece 34,
operated via the grip tab 52, which is for example accessible to an
operator from the window 15, optionally by means of an appropriate
tool.
[0060] This displacement compels the device 30 to deploy as
described in reference to FIGS. 4a to 5b. It is stopped when the
stop 49 arrives in contact with the first piece 32, or slightly
before this contact, as outlined in FIG. 8c. Regardless, the stop
49 prevents the second piece 34 from being shifted
circumferentially by too far, which could let it escape beyond the
first piece 32.
[0061] In reference now to FIG. 9, this shows a system 60
comprising two seconds pieces 34 intended to respectively enter the
constitution of two blocking devices 30. The two pieces 34, 34 are
joined together by the gripping member, here the tab 52 which is
therefore common to both devices. In this way, actioning the same
tab 52, for example at the level of its central portion in the form
of a V 62, it is advantageously possible to cause simultaneous
circumferential displacement of both pieces 34, 34 located on
either side of the common tab 52. Links 64 forming a mechanical
fuse can be made between the ends of the tab 52 and the second
pieces 34, 34, for example by providing notches. This controls the
breaking points in the event of the system 60 breaking, and adapts
the latter to its environment so that the tab 52 can easily be
recovered after the latter has been detached accidentally or
deliberately from the pieces 34.
[0062] An alternative shown in FIG. 10 is the same cable 52a
connecting the two pieces 34, 34 of the system 60.
[0063] A shown in FIGS. 11a and 11b, in the event of the system 60
of FIG. 9 being used, it suffices to actuate its central part 62 in
the form of a V to guide the two pieces 34, 34 by simultaneous
displacement, which tend to come together at the same time as they
allow the two relevant blocking devices to reach their deployed
configuration. In the case in point, the two last vanes introduced
6, as well as the two vanes adjacent to them (not shown), are
blocked circumferentially in both directions, respectively by the
two devices 30 sharing the same system 60. Also, it is noted that
in the event of breakage of one of the two vanes 6 situated between
the two devices 30, only these two vanes 6 can escape via the
window 15, as the others cannot reach this window due to the
presence of the two devices 30 forming bolts.
[0064] Actuation of the V 62 radially to the exterior can be done
using a hooked tool 66, cooperating with the base of the V open
radially to the interior, this tool being for example inserted in
the introduction window 15 passing between the platforms of the two
vanes 6, as outlined in FIG. 11a.
[0065] Once the V is pulled radially to the exterior by the
interior of its point, its angle is diminished and its length
extended, as shown in FIG. 11b. This deformation of the V tends to
be conserved by the effect of centrifugal force exerted on the
latter, during operation of the turbojet.
[0066] The V 62 could naturally be replaced by any other
appropriate form, such as a simple plane plate oriented
circumferentially, which would then deform progressively to take
the form of a V during actuation by the tool 66.
[0067] FIGS. 12a and 12b show that every second piece 34 can also
travel under one or more vane bases 6, and that this piece 34,
whether or not being integrated with a system 60 such as described
hereinabove. In the case in point, the stop 49 is located opposite
and possibly in contact with a vane base, and no longer near the
first piece 32 of the same blocking device, with which the second
piece 34 bearing this stop 49 cooperates.
[0068] FIGS. 13 and 14 show the possibility of providing locking
means of each device 30 in a radially deployed position. Specified
here is an elastic foot 68 coming from the first surface 46a,
capable of lodging in a housing 70 of the first piece 32, when the
two pieces reach their relative position giving the configuration
deployed. The foot 68 and the recess create relative blockage of
both pieces in the circumferential direction by way of this
cooperation, which can be unlocked only by exerting deliberate
action on said foot to create disengagement.
[0069] Naturally, these locking means can also be provided when the
system comprises the cable 52a as a link between the two second
pieces 64, as shown in FIG. 15. They are also applicable to the
insulated blocking devices 30, of the type described in reference
to FIGS. 3 to 8c.
[0070] Finally, FIGS. 16a and 16b show different steps ensuring
dismantling of the blocking devices 30. FIG. 16a shows that the
feet 68 are first disengaged from their recess by a tool 72
inserted in between the vane platforms. Also, for access to each
foot 68, the first piece 32 is equipped with an orifice 74 letting
the tool head 72 pass, and terminating in the recess 70. This
orifice 74 can be made at the time of dismantling, or when the
piece 32 is manufactured.
[0071] Next, as outlined in FIG. 16b, the pieces 34, 34 are shifted
circumferentially to unlock the blocking devices 30. This done for
example by inserting a tool 76 in between the vane platforms, in
the window 15, to lean the tool head against the point of the V 62
of the system 60. This support compels the system 60 to rediscover
its configuration such as shown in FIG. 12a, with the feet 68 also
arranged in a retracted position.
[0072] However, any other technique for circumferentially
displacing the second pieces 34, 34 can be adopted, without
departing from the scope of the invention.
[0073] Of course, various modifications can be made by the expert
to the invention which has just been described, solely by way of
non-limiting examples.
* * * * *